Gamma-ray spectroscopy of 38S and an application of machine learning to recoil event selection

A cura di Calem R. Hoffman (Argonne National Laboratory (USA))

mercoledì 24 feb 2021, 15:00 → 16:00 Europe/Rome

The interplay between various nuclear shells has elevated interest in the neutron-rich Z=14-16 and N>20 region of the nuclear chart in recent years. In particular, a consistent description is currently being sought after which accounts for both the merging of the neutron N=20 and 28 fp-shells, as well as the development of a new proton sub-shell closure at Z=14. We have approached this region through an empirical study of high-lying levels in 38S in an attempt to link similar configurations in this near-stable system to those with larger neutron-to-proton ratios. The measurement was conducted at the ATLAS Accelerator Facility, located at Argonne National Laboratory, USA. 38S nuclei were populated via fusion-evaporation, the GRETINA array surrounded the target position to provide detection of prompt gamma-ray emission, and the Fragment Mass Analyzer allowed for event-by-event recoil selection. A fully-connected neural network model was also developed to improve upon the 38S recoil event selection. Along with details pertaining to the experiment, analysis, and the updated 38S decay scheme, some preliminary discussions with respect to theoretical predictions and the systematic trends in the region will be presented.

 

https://unipd.zoom.us/j/85731741957?pwd=R09hTjk3WUdlOGJSS3FTNTI3OWZRUT09 (ZOOM)